1. Field of the Invention
The present invention relates to pharmaceutical preparations of etoposide, i.e. 4'-demethylepipodophillotoxin-9-(4,6-O-ethylidene-.beta.-D-glucopyranoside ), which is being put on the market as an antitumoral agent.
2. Description of the Prior Art
There is already known an etoposide preparation comprising an etoposide solution composition containing etoposide and a water-soluble cellulose ether derivative or polyvinylpyrrolidone (U.S. Pat. No. 4734284). Said preparation has been designed to show a reduced tendency to separate out crystals of etoposide, difficultly soluble in water, when added into water and an improved absorbability in a living body.
According to the Examples given in said U.S. Patent specification, however, the content of etoposide in the preparation is only 5-8%. Consequently it presents, when intended for use as encapsulated preparations, a problem of excessively large capsule size. Since etoposide is difficultly soluble in water, it has been very difficult to increase the etoposide content in its solution from the viewpoint of suppressing the separating out of its crystals which might occur when the solution is added into water.
Further, prior preparations show decrease in the etoposide content with lapse of time when tested under severe conditions, so that development of an etoposide preparation having enhanced stability for the lapse of time has been eagerly desired.